'Biggest Loser's new trainers Anna Kournikova, Dolvett Quince on joining the show and their ranch highlights

Biggest Loser will return with a new 'Battle of the Ages' theme and two new trainers when it premieres its 12th season tomorrow night on NBC. Professional tennis player and certified trainer Anna Kournikova and fitness expert Dolvett Quince will join returning trainer Bob Harper at the ranch as a new group of contestants arrive hoping to transform their lives by getting healthy.

Anna and Dolvett spoke to reporters about their experience joining Biggest Loser and what we can expect from the season:

Do you feel any added pressure coming in after Jillian Michaels and the departures of Brett Hoebel and Cara Castronuova?

Dolvett: "For me there is no added pressure because I have been doing personal training for so long and I'm very confident with being able to assist people and change their lives. I didn't come here with a mindset of being anything other than what I am and that's a trainer.

"It's a part of me and I love what I do and I wanted to translate that to these people, especially these obese people that could use my experience, so I walked into it with that confidence. I also had the confidence of an amazing support team on the show."

Anna: "I didn't feel any pressure. I was the one who went after this opportunity to be on the Biggest Loser and to be able to have the opportunity to train with these people and help them become healthier. I've worked with the best nutritionists, psychologists, coaches, trainers all those things and I have stored all of that information.

"I have used my body as a tool my whole life on the tennis court being a professional athlete so for me it was that instead of listening to the information that was thrown at me, I was sharing it with the contestants.

"I didn't feel like I was replacing anyone or trying to fill in anyone's shoes - we all have our own style. For me the biggest draw was that I had all this knowledge and I live and breathe sports, nutrition, well-being and helping people - for me that was the perfect combination. I've been working with kids in sports since 2003 and just promoting sports and healthy, active lifestyles so it was a completely natural role for me."

Anna, what would you say to people who have never seen you train before and would assume you have been picked for your looks?

"People always ask me how can you relate to the contestants? They are obese and they are this and that and I'm like, listen, I get criticized and judged all the time whether it's 'she's just too pretty', 'she's not good enough', 'she wasn't a good athlete' but to be a top ten in the world at something I must have been doing something right! I've achieved everything with my pure hard work and determination.

"I came from the Soviet Union and really nothing and a very modest background and that's why I tell the contestants I can relate to them and understand them. I know what it's like to be judged and criticized, whether it's because of your weight or how you look or people looking at you with all these pre-conceived notions. I'm okay with that. The only thing I can do and that I control is that I can work hard, be the best human being I can and that's it."

Watch Anna and Dolvett arriving at Biggest Loser below (US only):

Was the experience as you imagined it would be?

Anna: "It's definitely different. It's one thing watching it and another thing actually being there. You literally become family with these people. You care and become so involved and attached, but you always have to be careful. It's a fine balance. You still have to keep a little bit of a distance and a fresh perspective.

"I love the working out and spending time with the contestants, what I really don't like is the camera stuff because I've rather be working out! I've never been on a TV show and it drives me crazy waiting for the cameras to set up! I'd rather be exercising and burning the calories off!

"It's all-consuming but I was dedicated and committed - that's why I wanted to do the Biggest Loser. I knew I could be committed, my heart was in the right place and I had all the knowledge. I was focusing and treating it as a professional athlete and this is my life."

What have been your highlights of working on Biggest Loser?

Dolvett: "Of course to watch the transformation of some of the people, the challenges were never easy, it's still competitive so it is about a competitive edge and what people will do to ensure they are at the front; to watch some of the people bond. My personal experience has been great because I worked with an amazing crew every day. I loved going to work every day. I get along famously with Anna and Bob and the contestants. The energy is just good."

Anna: "Where do I begin? It's everything! It's the great moments, the tough moments, it's the rollercoaster - it's an emotional journey. There were amazing times when I saw the contestants succeed - a 63-year-old with a knee replacement get off the floor - and there were also sad moments where you see the disappointment on contestants' faces when they gain weight or something like that.

"We spent four months with these contestants and there were definitely some incredible moments and some disappointing moments, but overall the most important thing for me was to share as many tools as I could so they could take all that information they had learned and be able to apply and use it in their life after the ranch because sooner or later everyone is going home.

"The overall objective and goal of the whole season and experience was that these people not only lose weight while sequestered on the ranch but that they can sustain and maintain the healthy lifestyle and weight off the ranch."

Watch Anna and Dolvett in action at the gym (US only):

What did the Biggest Loser experience teach you about yourselves?

Dolvett: "When you help someone out you learn a lot about yourself at the same time. When someone is obese and dealing with those issues there is a lot of emotional attachment to that, it's not just weight, it's emotional issues and your background. For me personally, hearing some of the contestants' stories forced me to look at my own story and I actually had more things in common with some of the contestants this season than I admitted.

"As I'm helping them go through this journey it forces you to look at the person in the mirror and say, 'I'm not that different than you... I relate to you in more ways than I have admitted'. For me personally, I've been able to relate to the big stories. We all go through trials and tribulations, we just deal with our issues differently."

Anna: "It's a huge responsibility to go on the Biggest Loser and to help these people - you are their best friend and trainer and trying to listen to what they are going through - and I was only ready for that now. I don't think I could have handled it five or three years ago because I don't think I was mature enough or went through my own discovery journey.

"I have done all of this my whole life - it was basically being very disciplined, showing up, spending a lot of time in the gym and working physically and mentally hard. That's what you go through as a professional athlete. You get to a certain level where everyone is on the same level, you all play good tennis, so it becomes who is mentally tougher? Who can get to the finals and not the semi-finals?

"It was pretty comfortable for me falling back into a routine of working hard. It's not that I didn't learn about myself, it's just I understood how committed and dedicated I can be to something I believe in so much."

Why does Biggest Loser continue to draw people in?

Anna: "There are so many different stories and people can relate to one or more people. Everybody has such incredible stories, whether they are young or older, I think it's definitely a feel good, incredibly inspiring show and obviously these people have tried to do everything they can when they are home to lose the weight and change their lives around and most of the time you need a great support system and team and education to turn your life around. Everybody will be able to relate with at least one person one the show and I think that's what attracts the viewers."

Dolvett: "The attraction is, if it's not you yourself, you know a family member or friend that a contestant reminds you of. It's the ultimate soap opera. You see everyone go through their changes and what's more motivating than working out? Whether it's with your girlfriends doing yoga or working out doing a 5k, whatever it might be, that camaraderie is so relatable so people tap in for that as well. It's not easy but if you accomplish it it's the perfect hero story."

Anna: "For me, what works is balance and moderation but also indulging at times. If you don't do that you will fall off the wagon and overeat or overdo. I personally eat anything or any type of food that is out there - everything from pizza to burgers to healthy oatmeal. What really works is moderation and as I've gotten older I am really more conscious and focused on nutritional benefits of food.

"I try to stick to eating whole foods and natural foods and I work out five or six days a week as much as I can. That's my therapy and my me-time. I've been used to sweating since I started playing at 5 years old. I never really go more than two days without sweating it out at the gym or doing some kind of sport. I get anxiety actually if I don't work out!"

Dolvett: "My workout regiment is crazy - there is nothing I don't do. I involve everything from yoga, pilates, strength training, biometrics in a two-hour workout. Sometimes I only work out for an hour but I maximize my time. I love working out, it's a release for me. I do between five to six days a week.

"I think everyone should have a day of rest and I think everyone should indulge and have a cheat day personally, you don't want to be too extreme on one side that it just doesn't make sense. You have to have balance in the middle and enjoy life. That's what I practice and preach and live by with myself and my clients."